Metabolic simulations of multiple deletion mutants generated from the backbone models of E. coli (iBKEco52) and S. cerevisiae (iBKSce50, iBKSce50Δmit, and iBKSce50+7). The product yield and cell growth performance of the proper strains are shown for the production of 1-butanol from AcCoA (a and b), isobutanol from PYR (c and d), and 1-propanol from OAA (e and f). Open circles represent the data obtained from E. coli (iBKEco50); closed red, blue, and orange circles represent the data of original (iBKSce50), merged (iBKSce50Δmit), and expanded (iBKSce50+7) models of S. cerevisiae, respectively. iBKSce50Δmit is an hypothetical S. cerevisiae model derived by merging the cytosolic and mitochondrial networks into one compartment. iBKSce50+7 is a model of iBKSce50 expanded by the addition of 7 E. coli reactions. The cell growth rate data were represented by relative values. A cell growth rate level determined from the wild type model was arbitrary set at 1.